CN108981101B - Control method and control device of electronic expansion valve and unit - Google Patents
Control method and control device of electronic expansion valve and unit Download PDFInfo
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- CN108981101B CN108981101B CN201810689042.9A CN201810689042A CN108981101B CN 108981101 B CN108981101 B CN 108981101B CN 201810689042 A CN201810689042 A CN 201810689042A CN 108981101 B CN108981101 B CN 108981101B
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- 238000000034 method Methods 0.000 title claims abstract description 42
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 48
- 238000010257 thawing Methods 0.000 claims description 30
- 239000007788 liquid Substances 0.000 claims description 29
- 239000003507 refrigerant Substances 0.000 abstract description 12
- 238000011156 evaluation Methods 0.000 abstract 1
- 238000010977 unit operation Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 2
- 238000004378 air conditioning Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
- F24F11/63—Electronic processing
- F24F11/64—Electronic processing using pre-stored data
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
- F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
- F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
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- Electrically Driven Valve-Operating Means (AREA)
Abstract
The invention discloses a control method and a control device of an electronic expansion valve and a unit. The control method comprises the following steps: determining the superheat degree and the heat exchange temperature difference of the unit; and adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference. According to the invention, two factors of the heat exchange characteristic and the superheat degree of the unit can be systematically considered, and after comprehensive judgment and evaluation, a proper mode for adjusting the electronic expansion valve is selected. The refrigerant flow that passes through after the regulation can make superheat degree and heat transfer difference in temperature all be in suitable scope, from this, can improve the performance and the reliability of unit operation (especially under the low temperature condition).
Description
Technical Field
The invention relates to the technical field of units, in particular to a control method and a control device of an electronic expansion valve and a unit.
Background
At present, most heat pump units are provided with electronic expansion valves, for example, air conditioning units control the flow of refrigerant by using electronic expansion valves. And adjusting the electronic expansion valve according to the superheat degree of the evaporator is a common way to control the electronic expansion valve. However, when the heat pump unit operates at a lower temperature, the heat quantity absorbed by the refrigerant from the air is less, and the refrigerant is not enough to be completely evaporated, so that the superheat degree at the outlet of the evaporator is lower and even zero. When the electronic expansion valve is adjusted according to the degree of superheat, the unit of adjustment of the degree of superheat is usually 1 degree celsius. Under the condition of low temperature, the adjustment amplitude is smaller by the mode of adjusting the electronic expansion valve, so that the flow of the refrigerant does not meet the high-energy-efficiency operation of the unit, and the performance and the reliability of the unit are reduced.
Aiming at the problem that the performance of a unit can be reduced by an adjusting mode of an electronic expansion valve in the prior art, an effective solution is not provided at present.
Disclosure of Invention
The embodiment of the invention provides a control method and a control device of an electronic expansion valve and a unit, and aims to solve the problem that the performance of the unit is reduced by an adjusting mode of the electronic expansion valve in the prior art.
In order to solve the above technical problem, in a first aspect, the present invention provides a control method of an electronic expansion valve, the method including:
determining the superheat degree and the heat exchange temperature difference of the unit;
and adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
Further, the method for determining the superheat degree and the heat exchange temperature difference of the unit comprises the following steps:
acquiring an air suction temperature and an air suction pressure saturation temperature, and determining the superheat degree of the unit according to the air suction temperature and the air suction pressure saturation temperature; or acquiring the air suction temperature and the defrosting pipe temperature, and determining the superheat degree of the unit according to the air suction temperature and the defrosting pipe temperature; and the number of the first and second groups,
acquiring the temperature of an air pipe, the temperature of a liquid pipe, the temperature of water outlet and the temperature of water inlet; and determining the heat exchange temperature difference of the unit according to the air pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature.
Further, the superheat degree of the unit is determined according to the suction temperature and the suction pressure saturation temperature, and the superheat degree is achieved through the following formula:
the degree of superheat is the suction temperature-suction pressure saturation temperature.
Further, the superheat degree of the unit is determined according to the air suction temperature and the defrosting pipe temperature, and the superheat degree is achieved through the following formula:
the superheat degree is the suction temperature-defrosting tube temperature.
Further, according to the gas pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature, the heat exchange temperature difference is determined, and the method is realized through the following formula:
further, adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference comprises:
comparing the size relationship between the superheat degree and a first preset threshold value or a first preset interval to obtain a first result; and the number of the first and second groups,
comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result;
and adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
Further, adjusting the opening degree of the electronic expansion valve according to the first result and the second result comprises:
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than the second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of the second preset interval; controlling the opening degree of the electronic expansion valve to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to the first preset threshold value, or the superheat degree is positioned in the first preset interval or is smaller than the left end value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than the second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of the second preset interval; controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: the heat exchange temperature difference is equal to the second threshold value, or the heat exchange temperature difference is within the second preset interval, the opening degree of the electronic expansion valve is controlled to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to the first preset threshold value, or the superheat degree is positioned in the first preset interval or is smaller than the left end value of the first preset interval; the second result is: if the heat exchange temperature difference is equal to the second preset threshold value, or the heat exchange temperature difference is within the second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: if the heat exchange temperature difference is greater than the second threshold value, or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is equal to the first preset threshold value, or the superheat degree is located in the first preset interval; the second result is: if the heat exchange temperature difference is greater than the second preset threshold value, or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to decrease along with the decrease of the heat exchange temperature difference;
if the first result is: the superheat degree is smaller than the first preset threshold value, or the superheat degree is smaller than the left end point value of the first preset interval; the second result is: and if the heat exchange temperature difference is greater than the second preset threshold value or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the superheat degree.
In a second aspect, an embodiment of the present invention further provides an assembly, where the assembly is configured to execute the method in the first aspect, and the assembly includes: a main board and an electronic expansion valve;
the main board is connected with the electronic expansion valve and used for determining the superheat degree and the heat exchange temperature difference of the unit; and adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
Further, the unit further includes: an air suction temperature sensing bulb, a low pressure sensor, a defrosting temperature sensing bulb, an air pipe and air pipe temperature sensing bulb, a water outlet temperature sensing bulb, a liquid pipe and liquid pipe temperature sensing bulb and a water inlet temperature sensing bulb,
the air suction temperature sensing bulb is connected with the low-pressure sensor;
the low pressure sensor is used for detecting the suction pressure, wherein the suction pressure is used for determining the saturation temperature of the suction pressure;
the main board is respectively connected with the air suction temperature sensing bulb, the low-pressure sensor, the air pipe temperature sensing bulb, the water outlet temperature sensing bulb, the liquid pipe temperature sensing bulb and the water inlet temperature sensing bulb and is used for determining the superheat degree according to the air suction temperature and the air suction pressure saturation temperature; or determining the superheat degree according to the air suction temperature and the defrosting pipe temperature;
and determining the heat exchange temperature difference according to the air pipe temperature, the water outlet temperature, the liquid pipe temperature and the water inlet temperature.
Further, the main board is further configured to compare a size relationship between the superheat degree and a first preset threshold or a first preset interval to obtain a first result; comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result; and adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
Further, the unit further includes:
four-way valve, evaporator, high-pressure sensor, high-pressure switch, compressor, low-pressure switch and steam separator,
an oil port S of the four-way valve is connected to the air suction temperature sensing bulb, an oil port C of the four-way valve is connected to the evaporator, an oil port D of the four-way valve is connected to the high-pressure sensor, and an oil port E of the four-way valve is connected to the air pipe;
the evaporator is connected to the defrosting thermal bulb;
the electronic expansion valve is positioned between the defrosting bulb and the liquid pipe;
the high pressure sensor, the high pressure switch, the compressor, the low pressure switch, the steam separator and the low pressure sensor are sequentially connected.
In a third aspect, an embodiment of the present invention further provides a device for controlling an electronic expansion valve, where the device is configured to perform the method according to the first aspect, and the device includes:
the determining module is used for determining the superheat degree and the heat exchange temperature difference of the unit;
and the adjusting module is used for adjusting the opening of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
Further, the determining module is further configured to obtain an air suction temperature and an air suction pressure saturation temperature, and determine a superheat degree of the unit according to the air suction temperature and the air suction pressure saturation temperature; or acquiring the air suction temperature and the defrosting pipe temperature, and determining the superheat degree of the unit according to the air suction temperature and the defrosting pipe temperature; acquiring the temperature of the air pipe, the temperature of the liquid pipe, the temperature of water outlet and the temperature of water inlet; and determining the heat exchange temperature difference of the unit according to the air pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature.
Further, the adjusting module is further configured to compare a size relationship between the superheat degree and a first preset threshold or a first preset interval to obtain a first result; comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result; and adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
By applying the technical scheme of the invention, the opening degree of the electronic expansion valve is adjusted according to the superheat degree and the heat exchange temperature difference. Compared with the factor of only considering the degree of superheat, the method can systematically evaluate two factors of the heat exchange characteristic and the degree of superheat of the unit, after comprehensive judgment, a proper mode for adjusting the electronic expansion valve is selected, and the adjusted refrigerant flow can enable the degree of superheat and the heat exchange temperature difference to be in a proper range, so that the performance and the reliability of the unit during operation (particularly under the low-temperature condition) can be improved.
Drawings
Fig. 1 is a flow chart of a control method of an electronic expansion valve according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method of controlling an electronic expansion valve according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an assembly according to an embodiment of the present invention;
fig. 4 is a block diagram of a control device of an electronic expansion valve according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the following drawings and specific embodiments, it being understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.
In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.
In order to solve the problem that the performance of the unit is reduced by the adjustment mode of the electronic expansion valve in the related art, an embodiment of the present invention provides a control method of an electronic expansion valve, as shown in fig. 1, the method includes:
s101, determining the superheat degree and the heat exchange temperature difference of a unit;
and S102, adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
And adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference. Compared with the factor of only considering the degree of superheat, the method can systematically evaluate two factors of the heat exchange characteristic and the degree of superheat of the unit, after comprehensive judgment, a proper mode for adjusting the electronic expansion valve is selected, and the adjusted refrigerant flow can enable the degree of superheat and the heat exchange temperature difference to be in a proper range, so that the performance and the reliability of the unit during operation (particularly under the low-temperature condition) can be improved.
In one possible implementation, the heat exchange temperature difference may be a heat exchange temperature difference between water and a refrigerant in the water chiller. The step S101 of determining the superheat degree and the heat exchange temperature difference of the unit may include: acquiring an air suction temperature and an air suction pressure saturation temperature, and determining the superheat degree of the unit according to the air suction temperature and the air suction pressure saturation temperature; or acquiring the air suction temperature and the defrosting pipe temperature, and determining the superheat degree of the unit according to the air suction temperature and the defrosting pipe temperature; acquiring the temperature of the air pipe, the temperature of the liquid pipe, the temperature of water outlet and the temperature of water inlet; and determining the heat exchange temperature difference of the unit according to the air pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature.
In general, the above parameters can be obtained by relevant components of the unit, and the superheat degree of the unit can be determined according to the suction temperature-suction pressure saturation temperature or the suction temperature-defrosting pipe temperature. And solving the heat exchange temperature difference of the unit according to the following formula.
When the unit does not have a device for detecting the suction pressure, for example: in the case of a low pressure sensor, the evaporating temperature (i.e., the suction pressure saturation temperature) of the evaporator can be approximately replaced by the defrosting pipe temperature. This can increase the diversity of the manner of obtaining the degree of superheat. However, compared with the method that the low-pressure sensor is adopted to determine the suction pressure, then the suction pressure saturation temperature is calculated, and the calculated superheat degree is substituted into the formula to obtain the superheat degree, the temperature feedback is lagged, the calculated superheat degree is possibly inaccurate, and therefore the adjustment of the electronic expansion valve is not suitable. Therefore, it is recommended to calculate the degree of superheat by directly obtaining the saturation temperature of the suction pressure, where the conditions permit.
In one possible implementation manner, as shown in fig. 2, the step S102 of adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference includes:
step S201, comparing the size relationship between the superheat degree and a first preset threshold value or a first preset interval to obtain a first result; and the number of the first and second groups,
step S202, comparing the size relation between the heat exchange temperature difference and a second preset threshold value or a second preset interval to obtain a second result;
and S203, adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
In the actual operation process of the heat pump unit, the control of the superheat degree and the heat exchange temperature difference at a certain value is difficult to realize, and the control within a certain range is more consistent with the actual situation. The method shown in fig. 2 is adopted to determine the threshold value and the preset interval, the superheat degree and the heat exchange temperature difference are respectively compared with the threshold value and the preset interval, and the electronic expansion valve is adjusted according to the comparison result. The preset threshold value and the preset interval can be set according to the requirement of a user on the unit performance and the performance of the electronic expansion valve. It can be understood that the adjustment of the electronic expansion valve is more stable by adopting the preset interval as the reference value of the superheat degree or the heat exchange temperature difference, and the reliability is further improved. And the two modes can be used alternately. For example, the superheat degree is compared with a preset threshold value, and the heat exchange temperature difference is compared with a preset interval, so that a first comparison result and a second comparison result are obtained. The invention is not limited in this regard.
In one possible implementation, adjusting the opening degree of the electronic expansion valve according to the first result and the second result includes: if the first result is: the superheat degree is larger than a first preset threshold value, or the superheat degree is larger than a right end point value of a first preset interval; the second result is: the heat exchange temperature difference is smaller than a second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of a second preset interval; controlling the opening degree of the electronic expansion valve to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to a first preset threshold value, or the superheat degree is within a first preset interval or smaller than the left end point value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than a second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of a second preset interval; controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the degree of superheat is greater than a first preset threshold, or,
the superheat degree is larger than the right end point value of the first preset interval; the second result is: the heat exchange temperature difference is equal to a second threshold value, or the heat exchange temperature difference is within a second preset interval, the opening degree of the electronic expansion valve is controlled to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to a first preset threshold value, or the superheat degree is within a first preset interval or smaller than the left end point value of the first preset interval; the second result is: if the heat exchange temperature difference is equal to a second preset threshold value, or the heat exchange temperature difference is within a second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than a first preset threshold value, or the superheat degree is larger than a right end point value of a first preset interval; the second result is: if the heat exchange temperature difference is greater than a second threshold value, or the heat exchange temperature difference is greater than a right endpoint value of a second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is equal to a first preset threshold value, or the superheat degree is located in a first preset interval; the second result is: if the heat exchange temperature difference is greater than a second preset threshold value, or the heat exchange temperature difference is greater than a right endpoint value of a second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the heat exchange temperature difference;
if the first result is: the superheat degree is smaller than a first preset threshold value, or the superheat degree is smaller than the left end point value of a first preset interval; the second result is: and if the heat exchange temperature difference is greater than a second preset threshold value or the heat exchange temperature difference is greater than a right endpoint value of a second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the superheat degree.
In table 1, the reference standard of the degree of superheat is a first preset threshold value, and the reference standard of the heat exchange temperature difference is a second preset threshold value, in table 2, the reference standard of the degree of superheat is a first preset interval, the reference standard of the heat exchange temperature difference is a second preset interval, Δ t2 represents the degree of superheat, δ represents the first preset threshold value, Δ t1 represents the heat exchange temperature difference, ε represents the second preset threshold value, [ a, B ] represents the first preset interval, [ α ] represents the second preset interval, and EXV represents the electronic expansion valve.
TABLE 1
| Δt1＜ε | Δt1＝ε | Δt1＞ε | |
| Δt2＞δ | Opening up, adjusting according to the degree of superheat | Opening up, adjusting according to the degree of superheat | Not adjust EXV |
| Δt2＝δ | Not adjust EXV | Not adjust EXV | Small, adjusted according to heat exchange temperature difference |
| Δt2＜δ | Not adjust EXV | Not adjust EXV | Turning off, controlling by superheat |
TABLE 2
| Δt1＜α | Δt1＝[α，β] | Δt1＞β | |
| Δt2＞B | Opening up, adjusting according to the degree of superheat | Opening up, adjusting according to the degree of superheat | Not adjust EXV |
| Δt2＝[A，B] | Not adjust EXV | Not adjust EXV | Small, adjusted according to heat exchange temperature difference |
| Δt2＜A | Not adjust EXV | Not adjust EXV | Turning off, controlling by superheat |
It should be noted that the smaller the heat exchange temperature difference, the higher the performance of the unit is, and the higher the priority of adjusting the electronic expansion valve based on the superheat degree is than the priority of adjusting the electronic expansion valve based on the heat exchange temperature difference, taking table 1 as an example, when the heat exchange temperature difference of the unit is not greater than the second preset threshold and the superheat degree is not greater than the first preset threshold, the operation state of the unit is normal, that is, the refrigerant flow passing through the unit and the unit performance can be maintained in a stable balanced state due to the opening degree of the electronic expansion valve, and the electronic expansion valve does not need to be adjusted. If the heat exchange temperature difference is kept unchanged and the superheat degree is increased to be larger than a first preset threshold value, the electronic expansion valve is controlled to be opened according to the increase of the superheat degree. If the heat exchange temperature difference is larger than the second preset threshold value, and the superheat degree is equal to the first preset threshold value at the moment, the superheat degree is stable, and the electronic expansion valve is controlled to be closed according to the reduction of the heat exchange temperature difference. And if the heat exchange temperature difference is greater than a second preset threshold value and the superheat degree is less than a first preset threshold value, namely, the heat exchange temperature difference and the superheat degree are both unstable, controlling the electronic expansion valve to close according to the reduction of the superheat degree according to the priority.
Therefore, the opening degree of the electronic expansion valve is adjusted according to the superheat degree and the heat exchange temperature difference. Compared with the factor of only considering the degree of superheat, the method can systematically evaluate two factors of the heat exchange characteristic and the degree of superheat of the unit, after comprehensive judgment, a proper mode for adjusting the electronic expansion valve is selected, and the adjusted refrigerant flow can enable the degree of superheat and the heat exchange temperature difference to be in a proper range, so that the performance and the reliability of the unit during operation (particularly under the low-temperature condition) can be improved.
Fig. 3 shows an assembly for performing the method according to the above embodiment, the assembly comprising: a main board (not shown) and an electronic expansion valve 1;
the main board is connected with the electronic expansion valve 1 and used for determining the superheat degree and the heat exchange temperature difference of the unit; and adjusting the opening degree of the electronic expansion valve 1 according to the superheat degree and the heat exchange temperature difference.
In one possible implementation, the machine set further includes: an air suction temperature sensing bulb 2, a low pressure sensor 3, a defrosting temperature sensing bulb 4, an air pipe and air pipe temperature sensing bulb 5, a water outlet temperature sensing bulb 6, a liquid pipe and liquid pipe temperature sensing bulb 7 and a water inlet temperature sensing bulb 8,
the air suction temperature sensing bulb 2 is connected with a low-pressure sensor 3;
a low pressure sensor 3 for detecting a suction pressure, wherein the suction pressure is used for determining a suction pressure saturation temperature;
the main board is respectively connected with the air suction temperature sensing bulb 2, the low pressure sensor 3, the air pipe temperature sensing bulb 5, the water outlet temperature sensing bulb 6, the liquid pipe temperature sensing bulb 7 and the water inlet temperature sensing bulb 8 and is used for determining the superheat degree according to the air suction temperature and the air suction pressure saturation temperature; or determining the degree of superheat according to the air suction temperature and the defrosting pipe temperature; and determining the heat exchange temperature difference according to the air pipe temperature, the water outlet temperature, the liquid pipe temperature and the water inlet temperature.
In a possible implementation manner, the main board is further configured to compare a size relationship between the superheat degree and a first preset threshold or a first preset interval to obtain a first result; comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result; the opening degree of the electronic expansion valve 1 is adjusted based on the first result and the second result.
In one possible implementation, the machine set further includes: a four-way valve 9, an evaporator 10, a high-pressure sensor 11, a high-pressure switch 12, a compressor 13, a low-pressure switch 14 and a steam separator 15,
an S oil port of the four-way valve 9 is connected to the air suction temperature sensing bulb 2, an C oil port is connected to the evaporator 10, a D oil port is connected to the high pressure sensor 11, and an E oil port is connected to the air pipe 5;
the evaporator 10 is connected with the defrosting thermal bulb 4;
the electronic expansion valve 1 is positioned between the defrosting bulb 4 and the liquid pipe 7;
the high-pressure sensor 11, the high-pressure switch 12, the compressor 13, the low-pressure switch 14, the steam separator 15 and the low-pressure sensor 3 are sequentially connected.
And adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference. Compared with the factor of only considering the degree of superheat, the method can systematically evaluate two factors of the heat exchange characteristic and the degree of superheat of the unit, after comprehensive judgment, a proper mode for adjusting the electronic expansion valve is selected, and the adjusted refrigerant flow can enable the degree of superheat and the heat exchange temperature difference to be in a proper range, so that the performance and the reliability of the unit during operation (particularly under the low-temperature condition) can be improved.
Fig. 4 shows a control arrangement for an electronic expansion valve for performing the method of fig. 1 or 2, the arrangement comprising:
the determining module 401 is used for determining the superheat degree and the heat exchange temperature difference of the unit;
and the adjusting module 402 is used for adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
In a possible implementation manner, the determining module 401 is further configured to obtain an air suction temperature and an air suction pressure saturation temperature, and determine a superheat degree of the unit according to the air suction temperature and the air suction pressure saturation temperature; or acquiring the air suction temperature and the defrosting pipe temperature, and determining the superheat degree of the unit according to the air suction temperature and the defrosting pipe temperature; acquiring the temperature of the air pipe, the temperature of the liquid pipe, the temperature of water outlet and the temperature of water inlet; and determining the heat exchange temperature difference of the unit according to the air pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature.
In a possible implementation manner, the adjusting module 402 is further configured to compare a size relationship between the superheat degree and a first preset threshold or a first preset interval, so as to obtain a first result; comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result; and adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
In one possible implementation, the adjusting module 402 is further configured to, if the first result is: the superheat degree is larger than a first preset threshold value, or the superheat degree is larger than a right end point value of a first preset interval; the second result is: the heat exchange temperature difference is smaller than a second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of a second preset interval; controlling the opening degree of the electronic expansion valve to increase along with the increase of the superheat degree; if the first result is: the superheat degree is smaller than or equal to a first preset threshold value, or the superheat degree is within a first preset interval or smaller than the left end point value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than a second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of a second preset interval; controlling the opening degree of the electronic expansion valve to be unchanged; if the first result is: the superheat degree is larger than a first preset threshold value, or the superheat degree is larger than a right end point value of a first preset interval; the second result is: the heat exchange temperature difference is equal to a second threshold value, or the heat exchange temperature difference is within a second preset interval, the opening degree of the electronic expansion valve is controlled to increase along with the increase of the superheat degree; if the first result is: the superheat degree is smaller than or equal to a first preset threshold value, or the superheat degree is within a first preset interval or smaller than the left end point value of the first preset interval; the second result is: if the heat exchange temperature difference is equal to a second preset threshold value, or the heat exchange temperature difference is within a second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged; if the first result is: the superheat degree is larger than a first preset threshold value, or the superheat degree is larger than a right end point value of a first preset interval; the second result is: if the heat exchange temperature difference is greater than a second threshold value, or the heat exchange temperature difference is greater than a right endpoint value of a second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged; if the first result is: the superheat degree is equal to a first preset threshold value, or the superheat degree is located in a first preset interval; the second result is: if the heat exchange temperature difference is greater than a second preset threshold value, or the heat exchange temperature difference is greater than a right endpoint value of a second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the heat exchange temperature difference; if the first result is: the superheat degree is smaller than a first preset threshold value, or the superheat degree is smaller than the left end point value of a first preset interval; the second result is: and if the heat exchange temperature difference is greater than a second preset threshold value or the heat exchange temperature difference is greater than a right endpoint value of a second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the superheat degree.
And adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference. Compared with the factor of only considering the degree of superheat, the method can systematically evaluate two factors of the heat exchange characteristic and the degree of superheat of the unit, after comprehensive judgment, a proper mode for adjusting the electronic expansion valve is selected, and the adjusted refrigerant flow can enable the degree of superheat and the heat exchange temperature difference to be in a proper range, so that the performance and the reliability of the unit during operation (particularly under the low-temperature condition) can be improved.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a mobile terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
While the present invention has been described with reference to the embodiments illustrated in the drawings, the present invention is not limited to the embodiments, which are illustrative rather than restrictive, and it will be apparent to those skilled in the art that many more modifications and variations can be made without departing from the spirit of the invention and the scope of the appended claims.
Claims (13)
1. A method of controlling an electronic expansion valve, the method comprising:
determining the superheat degree and the heat exchange temperature difference of the unit;
adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference;
adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference comprises the following steps:
comparing the size relationship between the superheat degree and a first preset threshold value or a first preset interval to obtain a first result; and the number of the first and second groups,
comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result;
adjusting the opening degree of the electronic expansion valve according to the first result and the second result;
determining the heat exchange temperature difference of the unit comprises the following steps:
acquiring the temperature of an air pipe, the temperature of a liquid pipe, the temperature of water outlet and the temperature of water inlet; determining the heat exchange temperature difference of the unit according to the air pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature;
determining heat exchange temperature difference according to the gas pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature, and realizing the heat exchange temperature difference through the following formula:
2. the method of claim 1, wherein determining a superheat degree of the train comprises:
acquiring an air suction temperature and an air suction pressure saturation temperature, and determining the superheat degree of the unit according to the air suction temperature and the air suction pressure saturation temperature; or acquiring the air suction temperature and the defrosting pipe temperature, and determining the superheat degree of the unit according to the air suction temperature and the defrosting pipe temperature.
3. The method of claim 2, wherein the superheat of the train is determined from the suction temperature and the suction pressure saturation temperature by the following equation:
the degree of superheat is the suction temperature-suction pressure saturation temperature.
4. The method according to claim 2, characterized in that the degree of superheat of the unit is determined from the suction temperature and the defrosting pipe temperature, by the following formula:
the superheat degree is the suction temperature-defrosting tube temperature.
5. The method of claim 1, wherein adjusting the opening degree of the electronic expansion valve based on the first result and the second result comprises:
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than the second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of the second preset interval; controlling the opening degree of the electronic expansion valve to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to the first preset threshold value, or the superheat degree is positioned in the first preset interval or is smaller than the left end value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than the second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of the second preset interval; controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: the heat exchange temperature difference is equal to the second threshold value, or the heat exchange temperature difference is within the second preset interval, the opening degree of the electronic expansion valve is controlled to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to the first preset threshold value, or the superheat degree is positioned in the first preset interval or is smaller than the left end value of the first preset interval; the second result is: if the heat exchange temperature difference is equal to the second preset threshold value, or the heat exchange temperature difference is within the second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: if the heat exchange temperature difference is greater than the second threshold value, or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is equal to the first preset threshold value, or the superheat degree is located in the first preset interval; the second result is: if the heat exchange temperature difference is greater than the second preset threshold value, or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to decrease along with the decrease of the heat exchange temperature difference;
if the first result is: the superheat degree is smaller than the first preset threshold value, or the superheat degree is smaller than the left end point value of the first preset interval; the second result is: and if the heat exchange temperature difference is greater than the second preset threshold value or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the superheat degree.
6. An assembly for performing the method of any one of claims 1 to 5, the assembly comprising: a main board and an electronic expansion valve;
the main board is connected with the electronic expansion valve and used for determining the superheat degree and the heat exchange temperature difference of the unit; and adjusting the opening degree of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
7. The aggregate according to claim 6, characterized in that it further comprises: an air suction temperature sensing bulb, a low pressure sensor, a defrosting temperature sensing bulb, an air pipe and air pipe temperature sensing bulb, a water outlet temperature sensing bulb, a liquid pipe and liquid pipe temperature sensing bulb and a water inlet temperature sensing bulb,
the air suction temperature sensing bulb is connected with the low-pressure sensor;
the low pressure sensor is used for detecting the suction pressure, wherein the suction pressure is used for determining the saturation temperature of the suction pressure;
the main board is respectively connected with the air suction temperature sensing bulb, the low-pressure sensor, the air pipe temperature sensing bulb, the water outlet temperature sensing bulb, the liquid pipe temperature sensing bulb and the water inlet temperature sensing bulb and is used for determining the superheat degree according to the air suction temperature and the air suction pressure saturation temperature; or determining the superheat degree according to the air suction temperature and the defrosting pipe temperature;
and determining the heat exchange temperature difference according to the air pipe temperature, the water outlet temperature, the liquid pipe temperature and the water inlet temperature.
8. The assembly according to claim 6,
the main board is further used for comparing the size relationship between the superheat degree and a first preset threshold value or a first preset interval to obtain a first result; comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result; and adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
9. The aggregate according to claim 6, characterized in that it further comprises:
four-way valve, evaporator, high-pressure sensor, high-pressure switch, compressor, low-pressure switch and steam separator,
an oil port S of the four-way valve is connected to the air suction temperature sensing bulb, an oil port C of the four-way valve is connected to the evaporator, an oil port D of the four-way valve is connected to the high-pressure sensor, and an oil port E of the four-way valve is connected to the air pipe;
the evaporator is connected to the defrosting thermal bulb;
the electronic expansion valve is positioned between the defrosting bulb and the liquid pipe;
the high pressure sensor, the high pressure switch, the compressor, the low pressure switch, the steam separator and the low pressure sensor are sequentially connected.
10. An apparatus for controlling an electronic expansion valve, the apparatus being adapted to perform the method of any one of claims 1 to 5, the apparatus comprising:
the determining module is used for determining the superheat degree and the heat exchange temperature difference of the unit;
and the adjusting module is used for adjusting the opening of the electronic expansion valve according to the superheat degree and the heat exchange temperature difference.
11. The apparatus of claim 10,
the determining module is further used for acquiring an air suction temperature and an air suction pressure saturation temperature, and determining the superheat degree of the unit according to the air suction temperature and the air suction pressure saturation temperature; or acquiring the air suction temperature and the defrosting pipe temperature, and determining the superheat degree of the unit according to the air suction temperature and the defrosting pipe temperature;
and the number of the first and second groups,
acquiring the temperature of an air pipe, the temperature of a liquid pipe, the temperature of water outlet and the temperature of water inlet; and determining the heat exchange temperature difference of the unit according to the air pipe temperature, the liquid pipe temperature, the water outlet temperature and the water inlet temperature.
12. The apparatus of claim 10,
the adjusting module is further used for comparing the size relationship between the superheat degree and a first preset threshold value or a first preset interval to obtain a first result; comparing the heat exchange temperature difference with a second preset threshold value or a second preset interval to obtain a second result; and adjusting the opening degree of the electronic expansion valve according to the first result and the second result.
13. The apparatus of claim 12,
the adjusting module is further configured to, if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than the second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of the second preset interval; controlling the opening degree of the electronic expansion valve to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to the first preset threshold value, or the superheat degree is positioned in the first preset interval or is smaller than the left end value of the first preset interval; the second result is: the heat exchange temperature difference is smaller than the second preset threshold value, or the heat exchange temperature difference is smaller than the left end point value of the second preset interval; controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: the heat exchange temperature difference is equal to the second threshold value, or the heat exchange temperature difference is within the second preset interval, the opening degree of the electronic expansion valve is controlled to increase along with the increase of the superheat degree;
if the first result is: the superheat degree is smaller than or equal to the first preset threshold value, or the superheat degree is positioned in the first preset interval or is smaller than the left end value of the first preset interval; the second result is: if the heat exchange temperature difference is equal to the second preset threshold value, or the heat exchange temperature difference is within the second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is larger than the first preset threshold value, or the superheat degree is larger than a right end value of the first preset interval; the second result is: if the heat exchange temperature difference is greater than the second threshold value, or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to be unchanged;
if the first result is: the superheat degree is equal to the first preset threshold value, or the superheat degree is located in the first preset interval; the second result is: if the heat exchange temperature difference is greater than the second preset threshold value, or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to decrease along with the decrease of the heat exchange temperature difference;
if the first result is: the superheat degree is smaller than the first preset threshold value, or the superheat degree is smaller than the left end point value of the first preset interval; the second result is: and if the heat exchange temperature difference is greater than the second preset threshold value or the heat exchange temperature difference is greater than a right endpoint value of the second preset interval, controlling the opening degree of the electronic expansion valve to be reduced along with the reduction of the superheat degree.
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| CN110986253B (en) * | 2019-11-15 | 2022-04-29 | 珠海格力电器股份有限公司 | Electronic expansion valve control method, compressor control system and air conditioner |
| CN111121290B (en) * | 2019-12-19 | 2021-11-09 | 宁波奥克斯电气股份有限公司 | Control method and control device of electronic expansion valve and heat pump water heater |
| CN113551379B (en) * | 2020-04-26 | 2022-09-13 | 青岛海尔空调电子有限公司 | Expansion valve opening degree control method for air conditioning system |
| CN113701873A (en) * | 2020-05-19 | 2021-11-26 | 广州汽车集团股份有限公司 | Refrigerant flow sound detection device, system and method |
| CN113742833B (en) * | 2021-09-17 | 2024-08-02 | 上海美控智慧建筑有限公司 | Setting method and device of air conditioner room and electronic equipment |
| CN115265012B (en) * | 2022-07-08 | 2024-01-12 | 珠海格力电器股份有限公司 | Electronic expansion valve opening control method, system and unit |
| CN115493295B (en) * | 2022-09-26 | 2024-07-12 | 珠海格力电器股份有限公司 | Control method and system of hot water unit and computer readable storage medium |
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